LU-15074 build: Use strlcpy if strscpy is not available

LU-15074 build: Use strlcpy if strscpy is not available

Linux commit v4.2-rc1-2-g30035e45753b
    string: provide strscpy()

    The strscpy() API is intended to be used instead of strlcpy(),
    and instead of most uses of strncpy().

Unfortunatley strscpy is not always available.

Test for strscpy and fallback to strlcpy when strscpy is
not available.

Test-Parameters: trivial
Fixes: b77a6d86936 ("LU-14665 lnet: simplify lnet_ni_add_interface")
HPE-bug-id: LUS-9546
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I43038e4a6260dafb57195ec3417ce009f5a3fad4
Reviewed-on: https://review.whamcloud.com/45175
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>